1. Field of the Invention
The present invention relates to a trim cover attachment member of a vehicle seat, a manufacturing method thereof and a vehicle seat.
2. Description of Related Arts
In general, as shown in FIG. 5, a vehicle seat 10 or 20 comprises a seat cushion 101 or 201, a seat back 12 provided at the rear side of the seat cushion 101 or 201, or the like. As shown in the longitudinal sectional view in FIG. 6, the seat cushion 101 or 201 comprises a seat frame 2, a pad member 3, a trim cover 4 as a covering member which covers the pad member 3, or the like. A J-shaped hook member 100 or 200 for attachment of the trim cover 4 (hereinafter, a hook member 100 or 200), which is made of resin, is sewn on an end portion 4a of the trim cover 4. The hook member 100 or 200 is engaged with an engaging portion 21 provided at the end portion of the seat frame 2. Thereby, disposing of the end portion 4a of the trim cover 4 is performed.
Incidentally, in the hook member 100 shown in FIG. 7, a plurality of slits 111, 111 . . . are provided at the portion corresponding to the corner portion 101a (c.f. FIG. 5) of the seat cushion 101 by punching, so as to form a slit portion 110. The slits 111, 111 . . . are provided with a length, for example, from the bottom end portion toward the mid-way of the upper end portion in the width direction of the hook member 100. Thereby, when bending is carried out in order to make the slit portion 110 correspond to the corner portion 101a, the slit portion 110 can follow the shape of the corner portion 101a. 
Further, the hook member 200 is formed by a metallic core reinforcement 210, and a covering member 220 made of flexible resin such as, vinyl chloride resin or the like. Although no slit is formed at the bottom end portion in the width direction of the hook member 200, slits 211, 211 . . . are formed at the upper end portion of the core reinforcement 210. Therefore, it can follow the shape of the corner portion 201a when bending is performed.
Here, xe2x80x9cwidth directionxe2x80x9d is the direction orthogonal to the longitudinal direction of the hook members 100 and 200, that is, the top-to-bottom direction in FIGS. 7 and 8.
However, when the hook member 100 shown in FIG. 7 is covered with the trim cover 4, since there are the slits 111, 111 . . . at the bottom end portion in the width direction of the hook member 100, for example, as shown in FIG. 9, the trim cover 4 is buried into the slits 111, 111 . . . by tension of the trim cover 4 and concave portions 121, 121 . . . are formed. Thereby, the surface of the trim cover 4 in the corner portion 101a is seen uneven, so that there is a problem that it is bad in appearance.
On the other hand, in the case of the hook member 200 shown in FIG. 8, since the whole core reinforcement 210 is covered with the covering member 220, the surface of the trim cover 4 in the corner portion 201a of the seat cushion 20 is not seen uneven when the hook member 200 is covered with the trim cover 4, so that there is no problem in appearance. However, since two materials, the core reinforcement 210 and the covering member 220, are formed integrally, there is a problem that the cost becomes high compared with the above-mentioned hook member 100.
The present invention was made in view of the above-described problems. An object of the present invention is to provide a trim cover attachment member of a vehicle seat, a manufacturing method thereof and a vehicle seat, which can improve quality of appearance in the corner portion of the vehicle seat when a trim cover attachment member of a vehicle seat is covered with a trim cover, and which can prevent cost rise.
In order to solve the above-described problems, according to a first aspect of the present invention, a trim cover attachment member of a vehicle seat, being attached to an end portion of a trim cover, and being engaged with an engaging portion provided at a seat frame of the vehicle seat, comprises: an attachment portion to which the end portion of the trim cover is attached; a hook portion having a hook on an upper end thereof, the hook being engaged with the engaging portion, the hook portion being disposed generally in opposite to the attachment portion; and a bottom portion for connecting a bottom end of the attachment portion and a bottom end of the hook portion. A cut-out portion is formed at a portion of the upper end of the hook portion, and an opening portion is formed at a portion of the attachment portion, in a portion of the trim cover attachment member corresponding to a corner portion of the vehicle seat.
Preferably, a plurality of the cut-out portions and the opening portions are provided in succession along a longitudinal direction of the trim cover attachment member. Further, the cut-out portion and the opening portion may be formed by punching.
More preferably, the attachment portion, the hook portion, and the bottom portion are formed integrally. Further, the bottom portion may be formed continuously along a longitudinal direction of the trim cover attachment member.
Moreover, a shape of the opening portion may be one of a round shape, a square shape, and a slit shape. In addition, the attachment portion, the hook portion, and the bottom portion are preferably made of synthetic resin.
According to the present invention, when bending is performed to the trim cover attachment member along the corner portion of the seat frame, the difference of volume of deformation caused by the difference between the radius of curvature of the attachment portion and the hook portion is absorbed by the cut-out portion and the opening portion which is formed at a portion of the attachment portion. Thereby, the followability of the shape of the corner portion can be maintained. Simultaneously, since the bottom portion is preferable to have a continuous shape, unevenness on the surface by tension of the trim cover cannot be seen when the trim cover attachment member is covered with the trim cover. Therefore, quality of appearance in the corner portion of the vehicle seat can be improved.
Furthermore, as in general, the cut-out portion and the opening portion may be formed by punching, manufacturing cost of the trim cover attachment member does not rise.
Further, in the present invention, since a plurality of the cut-out portions and the opening portions are preferably provided along the longitudinal direction of the trim cover attachment member, degree of freedom of radius of curvature of the corner portion to which the trim cover attachment member can follow becomes high. In other words, range of radius of curvature of the corner portion to which the trim cover attachment member may become wider.
According to a second aspect of the present invention, a vehicle seat comprises: a trim cover; a seat frame having an engaging portion; and a trim cover attachment member being attached to an end portion of the trim cover, and being engaged with the engaging portion of the seat frame. The trim cover attachment member comprises: an attachment portion to which the end portion of the trim cover is attached; a hook portion having a hook on an upper end thereof, the hook being engaged with the engaging portion, the hook portion being disposed generally in opposite to the attachment portion; and a bottom portion for connecting a bottom end of the attachment portion and a bottom end of the hook portion. A cut-out portion is formed at a portion of the upper end of the hook portion, and an opening portion is formed at a portion of the attachment portion, in a portion of the trim cover attachment member corresponding to a corner portion of the vehicle seat.
Preferably, a plurality of the cut-out portions and the opening portions are provided in succession along a longitudinal direction of the trim cover attachment member. Further, the cut-out portion and the opening portion may be formed by punching.
More preferably, the attachment portion, the hook portion, and the bottom portion are formed integrally. Further, the bottom portion may be formed continuously along a longitudinal direction of the trim cover attachment member.
Moreover, a shape of the opening portion may be one of a round shape, a square shape, and a slit shape. In addition, The attachment portion, the hook portion, and the bottom portion are preferably made of synthetic resin.
According to the vehicle seat, the same effect as the above-described first aspect of the present invention can be obtained.
According to a third aspect of the present invention, a method for manufacturing a trim cover attachment member of a vehicle seat, the trim cover attachment member being attached to an end portion of a trim cover and being engaged with an engaging portion provided at a seat frame of the vehicle seat, comprises: forming an attachment portion to which the end portion of the trim cover is attached, a hook portion having a hook for being engaged with the engaging portion on an upper end thereof, the hook portion being disposed generally in opposite to the attachment portion, and a bottom portion for connecting a bottom end of the attachment portion and a bottom end of the hook portion; and forming a cut-out portion at a portion of the upper end of the hook portion and an opening portion at a portion of the attachment portion, in a portion of the trim cover attachment member corresponding to a corner portion of the vehicle seat.
Preferably, the cut-out portion and the opening portion are formed by punching.